Purpose: To describe intraocular clouding of silicone oil in the absence of emulsification.
Methods: Retrospective observational case series of patients who received silicone oil injections and developed silicone oil discoloration without emulsification after pars plana vitrectomy. Clinical examinations and physicochemical analyses were performed to find out the common cause for the opaque oil.
Results: Thirteen patients developed silicone oil discoloration after pars plana vitrectomy. It could be traced down that all patients had received silicone oil from one respective production batch. The silicone oil was removed as soon as possible after the changes were detected (range, 8-16 weeks). Gas chromatography flame ionization detector, size exclusion chromatography, and high-performance liquid chromatography analysis showed the absence of low-molecular-weight compounds in the opaque lot. Thermogravimetric analysis revealed the opaque lot was more temperature stable. During the follow-ups, no obvious retinal toxicity could be observed and best-recorded visual acuity improved considerably in 12 patients and was only limited by the underlying retinal pathologic conditions.
Conclusion: This is the first report on opacification of intraocular silicone oil without emulsification. This discoloration of silicone oil may disturb vision and prevent proper fundus examination; however, it seems to be a nontoxic phenomenon without serious long-term consequences.